/*
** The string z[] is an ascii representation of a real number.
** Convert this string to a double.
**
** This routine assumes that z[] really is a valid number. If it
** is not, the result is undefined.
**
** This routine is used instead of the library atof() function because
** the library atof() might want to use "," as the decimal point instead
** of "." depending on how locale is set. But that would cause problems
** for SQL. So this routine always uses "." regardless of locale.
*/
int sqlite3AtoF(const char *z, double *pResult){
#ifndef SQLITE_OMIT_FLOATING_POINT
int sign = 1;
const char *zBegin = z;
LONGDOUBLE_TYPE v1 = 0.0;
while( isspace(*z) ) z++;
if( *z=='-' ){
sign = -1;
z++;
}else if( *z=='+' ){
z++;
}
while( isdigit(*(u8*)z) ){
v1 = v1*10.0 + (*z - '0');
z++;
}
if( *z=='.' ){
LONGDOUBLE_TYPE divisor = 1.0;
z++;
while( isdigit(*(u8*)z) ){
v1 = v1*10.0 + (*z - '0');
divisor *= 10.0;
z++;
}
v1 /= divisor;
}
if( *z=='e' || *z=='E' ){
int esign = 1;
int eval = 0;
LONGDOUBLE_TYPE scale = 1.0;
z++;
if( *z=='-' ){
esign = -1;
z++;
}else if( *z=='+' ){
z++;
}
while( isdigit(*(u8*)z) ){
eval = eval*10 + *z - '0';
z++;
}
while( eval>=64 ){ scale *= 1.0e+64; eval -= 64; }
while( eval>=16 ){ scale *= 1.0e+16; eval -= 16; }
while( eval>=4 ){ scale *= 1.0e+4; eval -= 4; }
while( eval>=1 ){ scale *= 1.0e+1; eval -= 1; }
if( esign<0 ){
v1 /= scale;
}else{
v1 *= scale;
}
}
*pResult = sign<0 ? -v1 : v1;
return z - zBegin;
#else
return sqlite3atoi64(z, pResult);
#endif /* SQLITE_OMIT_FLOATING_POINT */
}
/*
** Return some kind of integer value which is the best we can do
** at representing the value that *pMem describes as an integer.
** If pMem is an integer, then the value is exact. If pMem is
** a floating-point then the value returned is the integer part.
** If pMem is a string or blob, then we make an attempt to convert
** it into a integer and return that. If pMem is NULL, return 0.
**
** If pMem is a string, its encoding might be changed.
*/
i64 sqlite3VdbeIntValue(Mem *pMem) {
int flags = pMem->flags;
if( flags & MEM_Int ) {
return pMem->i;
} else if( flags & MEM_Real ) {
return (i64)pMem->r;
} else if( flags & (MEM_Str|MEM_Blob) ) {
i64 value;
if( sqlite3VdbeChangeEncoding(pMem, SQLITE_UTF8)
|| sqlite3VdbeMemNulTerminate(pMem) ) {
return SQLITE_NOMEM;
}
assert( pMem->z );
sqlite3atoi64(pMem->z, &value);
return value;
} else {
return 0;
}
}
